For various reasons the two locations have separate inventory.

Instead of placing all your money on one stock, spread it out among three separate stocks.

You should not put all your money in one stock and instead spread it among several stocks.

These runs are considered distinct stocks because they do not interbreed.

Some species form a single stock (e.g. southern bluefin tuna) while others are composed of several stocks (e.g. albacore tuna in the Pacific Ocean comprises separate Northern and Southern stocks).

Some species form a single stock (e.g. southern bluefin tuna) while others form several stocks (e.g. albacore tuna in the Pacific Ocean are divided up into separate Northern Pacific and Southern Pacific stocks).

In the Atlantic Ocean, bluefin tuna are managed as two separate stocks, an Eastern Atlantic and Mediterranean, and a Western.

Atlantic bluefin tuna are managed as two separate stocks: an eastern Atlantic and Mediterranean stock, and a western stock.